Typical ICDs include high voltage capacitors for delivering defibrillation shocks to a patient. In order for ICDs to maintain fast charge times for defibrillation shocks, the high voltage capacitors must be periodically “formed.” Forming the capacitors requires charging them to at least full energy (e.g., 36 Joules) once every several months (e.g., every three months). At battery mid-life, the capacitors may be formed more frequently (e.g., every month) in order to manage an ICD battery voltage delay phenomenon.
Capacitor reformation reduces the longevity of the ICD battery. Furthermore, after capacitor reformation, the charge on the high voltage capacitors is essentially wasted because the charge is not used for a defibrillation shock or for any other purpose.
What is needed, therefore, are methods and systems for decreasing the amount of energy used for ICD capacitor reformation, thereby increasing the longevity of the ICD battery.